Programmable logic switches are devices to control on and off of a logic switch such as a transistor, for example, in accordance with data stored in a memory. Such programmable logic switches are generally used in Field Programmable Gate Arrays (FPGAs) and the like which require reconfiguration of an arithmetic logic circuit and a wiring circuit.
A volatile memory such as an SRAM is used in a programmable logic switch used for a FPGA. Data stored in an SRAM are lost when the power is turned off. Accordingly, programmable switches using a volatile memory have a problem that data needs to be read again from a separately-provided memory region when the power is supplied again.
In general, an SRAM is formed of six transistors. For this reason, FPGAs including a large number of SRAMs have a problem of being large in chip area.